unconfirmed_users = ['alice', 'brain', 'candace']
confirmed_users = []
while unconfirmed_users:
    current_user =unconfirmed_users.pop()

    print(f"\nVerifying user:{current_user.title()}")
    confirmed_users.append(current_user)

#显示以核验的用户
print("\nThe following users have been confirmed:")
for confirmed_user in confirmed_users:
    print(confirmed_user.title())